The present invention relates to digital image processing circuitry, which has utility in the interpretation of electronic images generated, for example, from photographs or other forms of imaging in which it is necessary to process electronic images in order to interpret or to extract the data contained in the image, e.g., in interpreting or extracting image data acquired by satellite photography or in interpreting or extracting image data in acquired search fingerprints or file fingerprints.
In an automatic fingerprint identification system for matching search fingerprints to file fingerprints, of the kind described in Larcher et al. U.S. Pat. No. 4,790,564, issued Dec. 13, 1988 and entitled AUTOMATIC FINGERPRINT IDENTIFICATION SYSTEM INCLUDING PROCESSES AND APPARATUS FOR MATCHING FINGERPRINTS, the apparatus comprises a plurality of different subsystems communicating via a high-speed local area (LAN) network. Three of these subsystems are a ten print card input subsystem, a latent print input subsystem, and an encoding subsystem. The outputs of the print subsystems include analog or gray scale electronic images of fingerprints, which are subjected to digital image processing and digital image filtering. One drawback of conventional digital image processing and digital image filtering methods and apparatus is the large time overhead involved in performing the necessary image processing and image filtering computations.
In some cases, the image quality of the gray scale image outputs is directly related to the quality of the respective print inputs to the two subsystems and those of ordinary skill in the art have sought to improve image quality by means of digital image processing and digital image filtering.
The encoding subsystem described in the '564 patent includes appropriate circuit means for utilizing the electronic images to detect the minutiae in each fingerprint. Poor image quality has an adverse effect on the process of detecting minutiae. Poor image quality also has an adverse effect on correctly interpreting or extracting electronic image data acquired by satellite photography or other means.
Hence, the capability of increasing the speed of making digital image filtering and digital image processing computations and the capability of improving the quality of digital images by means of digital image filtering and digital image processing are goals sought after by those of ordinary skill in the art.